Thesis (Ph. D.) -- University of Western Sydney, Hawkesbury, 2000. / Includes bibliographical references (leaves 225-241).

Thesis (M. App. Sc.)--Carleton University, 2001. / Includes bibliographical references (p. 159-164). Also available in electronic format on the Internet.

Thesis (M.App.Sc.) - Carleton University, 2002. / Includes bibliographical references (p. 108-112). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December, 2008." Includes bibliographical references (leaves 227-228). Online version available on the World Wide Web.

Thesis (Ph.D) -- University of Western Sydney, 2006. / A thesis submitted to the University of Western Sydney, College of Health and Science, School of Engineering, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references.

Diss.--Technische Hochschule, Karlsruhe. / Description based on print version record. Bibliography: p. 109.

Thesis (M.C.E.)--University of Delaware, 2006. / Principal faculty advisor: Dennis R. Mertz, Dept. of Civil and Environmental Engineering. Includes bibliographical references.

This research embodied a three-prong approach for directly determining the residual prestress force of prestressed concrete bridge girders. For bridges that have yet to be constructed, outfitting girders with instrumentation is a highly effective means of determining residual prestress force in prestressed concrete bridge girders. This constitutes the first prong. Still, many bridges are constructed without such instrumentation. For these bridges, a destructive technique can be used to directly determine the residual prestress in a prestressed concrete bridge girder. This implies that the girder(s) being tested have already been taken out of service. This constitutes the second prong. For bridges that are anticipated to remain in service that are lacking embedded instrumentation, the development of a non-destructive technique used to estimate the remaining force in the tendons of prestressed bridge girders is extremely important. This constitutes the third prong used to directly determine residual prestress force. The flexural capacity was also determined from field tests and compared to analytical estimates. By design, the code estimates are meant to be conservative. Alternatively, the residual prestress force for in-service members can be determined directly through the non-destructive technique presented in this research. As such, bridge service capacities can be determined directly and do not need to be conservatively estimated. (231 pages)

The Icy Springs Bridge in Coalville, Utah carries 2nd South Street over the Weber River west of Interstate 80. The bridge is owned by Coalville City and was originally constructed in 1965 as a single-span 51-foot long bridge using prestressed concrete double-tee girders. In the fall of 2013 the original bridge was replaced with a new 80-foot long single span bridge using prestressed concrete decked bulb-tee girders. The original girders were salvaged and transported to the Systems, Materials, and Structural Health Lab (SMASH Lab) where a series of tests were performed to determine the total losses in the prestressing of the strands, the flexural and shear capacities of the girders, and the punching shear capacity of the reinforced concrete deck. The results of these tests were compared to the values calculated using methods outlined in the 2012 American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) Bridge Design Specifications, the current bridge design code used by most departments of transportation, and a finite element model using the computer program ANSYS. For the shear and punching shear test results, the AASHTO LRFD Bridge Design Specifications was conservative and was able to predict the type of failure that occurred. However, the tested flexural results were below the calculated flexural capacities using the AASHTO LRFD Bridge Design Specifications. A finite element model was created and calibrated to the test results for the various loading and support conditions. The actual tested material properties were compared to the material properties used in the finite element analyses to determine the difference between the actual girders and the theoretical models. Funding for this project was provided by the Utah Transportation Center.

During the fall of 2012, two separate Interstate 15 highway bridges over the 400 South roadway in Orem, Utah were demolished after 50 years of service. Four post-tensioned girders were salvaged from both the north-bound and south-bound bridge. A series of tests was performed with these girders in the System Material And Structural Health Laboratory (SMASH Lab). The girders were tested with different loading criteria to determine the strength and material properties of the girder. The experimental results were compared with the American Association of State Highway and Transportation Officials Load Resistance Factored Design (AASHTO LRFD) Bridge Design Specifications and a finite-element model using ANSYS. The AASHTO LRFD Specification was fairly conservative on predicting capacity and capable of predicting the type of failure that occurred. The ANSYS model was developed and calibrated to model the girder behavior. The concrete properties in the model were significantly adjusted in order to be comparable to the experimental results. Further exploration in ANSYS needs to be done to precisely model the actual behavior of the girder.